School of Environment, South China Normal University, 378 Waihuan West Road, Guangzhou 510006, China E-mail:
Water Sci Technol. 2022 May;85(10):2928-2944. doi: 10.2166/wst.2022.121.
The persistence of antibiotics in sewage treatment plants in recent years has become a serious problem. Meanwhile, humic acid and ammonia nitrogen are widely distributed in natural reservoirs and might influence the sorption, migration and transformation of antibiotics. In this study, natural zeolite (NZ) was evaluated as an adsorbent for the removal of levofloxacin (LEV). The physical and chemical properties of NZ before and after adsorption were characterized by various analytical techniques to develop the mechanism. The effects of ammonia nitrogen and humic acid (HA) on the interfacial behavior of LEV on NZ were explored. Comparative experiments revealed that LEV adsorption on NZ involved electrostatic interactions and ion exchange, and the adsorption processes were well fitted by the Langmuir isotherm model and pseudosecond-order kinetic model. The maximum experimental adsorption capacity of LEV was 22.17 mg·g at pH 6.5. The presence of ammonia nitrogen and HA significantly suppressed the adsorption of LEV due to competitive adsorption, and the adsorption capacity decreased 58 and 46%, respectively. It is obvious that low concentrations of ammonia nitrogen and HA are conducive to improving the treatment effect of sewage. This study demonstrates that NZ is a promising and efficient material for LEV adsorption.
近年来，污水处理厂中抗生素的持久性已成为一个严重的问题。同时，腐殖酸和氨氮广泛分布于天然水库中，可能会影响抗生素的吸附、迁移和转化。在这项研究中，天然沸石（NZ）被评估为一种用于去除左氧氟沙星（LEV）的吸附剂。采用各种分析技术对 NZ 吸附前后的物理化学性质进行了表征，以开发其作用机制。探讨了氨氮和腐殖酸（HA）对 LEV 在 NZ 上界面行为的影响。对比实验表明，LEV 在 NZ 上的吸附涉及静电相互作用和离子交换，吸附过程很好地符合朗缪尔等温模型和拟二级动力学模型。在 pH 值为 6.5 时，LEV 的最大实验吸附容量为 22.17mg·g。氨氮和 HA 的存在由于竞争吸附而显著抑制了 LEV 的吸附，吸附容量分别降低了 58%和 46%。显然，低浓度的氨氮和 HA 有利于提高污水的处理效果。本研究表明，NZ 是一种用于 LEV 吸附的有前途且高效的材料。
